Miniature magnetic mercury-wetted relay construction

Abstract

A miniature magnetic, mercury-wetted relay construction for achieving optimum magnetic reluctance in its operating flux path and thereby improving relay sensitivity. The dimensions of the armature of the relay are determined for maximum flux-carrying capacity without sacrifice of flexibility by mounting the armature to the relay stem by means of a thin, magnetic hinge. At the pole-piece end of the relay, a recess is provided within which the contact is mounted, the recess forming a flux concentrator projection of the pole-piece which extends outwardly therefrom toward the opposing face of the armature. Reluctance of the flux closure path is further reduced by providing an integral extension of the stem toward the end of the pole-piece which extension advantageously acts as a parallel flux path shunting the small gap presented at the armature end and an end of the stem. By forming the shunt extension integrally with the stem, joint reluctance is eliminated.

What is claimed is: 
     
       1. A miniature magnetically responsive, mercury-wetted relay construction comprising a magnetic stem member, a magnetic pole-piece member, means for oppositely supporting said stem and pole-piece members, armature means, a magnetic hinge for flexibly mounting said armature means on said stem member to extend over an overlap portion of said pole-piece member, said overlap portion having a recess formed therein to present a surface opposite one face of said armature means, an electrical contact mounted on said pole-piece member on said recess surface spaced apart from said opposite one face of said armature means, and flux concentrator means for concentrating magnetic flux between said pole-piece member and said armature means comprising a projection of said pole-piece member at said overlap portion formed by said recess, said projection extending from said pole-piece member toward said one face of said armature means. 
     
     
       2. A miniature magnetically responsive, mercury-wetted relay construction as claimed in claim 1 also comprising magnetic shunt means comprising an integral extension of said stem member toward said pole-piece member presenting a surface substantially parallel to said one face of said armature means. 
     
     
       3. A miniature magnetically responsive, mercury-wetted relay construction as claimed in claim 2 also comprising winding means associated with said construction energizable for generating a magnetic field for actuating said armature means. 
     
     
       4. A miniature magnetically responsive, mercury-wetted relay construction comprising a magnetic stem member, a magnetic pole-piece member, means for oppositely supporting said stem and pole-piece members, armature means, a magnetic hinge for flexibly mounting said armature means on said stem member to extend over an overlap portion of said pole-piece member, one end of said armature member presenting a small gap with the end of said stem member, said overlap portion having a recess formed therein to present a surface opposite one face of said armature means, an electrical contact mounted on said pole-piece member on said recess surface spaced apart from said opposite one face of said armature means, flux concentrator means for concentrating magnetic flux between said pole-piece member and said armature means comprising a projection of said pole-piece member at said overlap portion formed by said recess, said projection extending from said pole-piece member toward said one face of said armature means, and magnetic shunt means comprising an integral extension of said stem member beyond said end toward said pole-piece member bypassing said gap and presenting a surface substantially parallel to said one face of said armature means. 
     
     
       5. In a magnetic, mercury-wetted relay construction having oppositely mounted pole-piece and stem members and an armature member extending from said stem member to said pole-piece member, a low reluctance operating flux path comprising a thin, magnetic hinge for flexibly mounting said armature member to said stem member and a flux concentrator extension of said pole-piece member extending outwardly from a contact-bearing surface of said pole-piece member toward an opposing face of said armature member. 
     
     
       6. In a relay construction as claimed in claim 5, said operating flux path further comprising a magnetic shunt member integral with and extending from said stem member parallel with said armature member and toward said pole-piece member. 
     
     
       7. In a magnetic, mercury-wetted relay construction having oppositely mounted pole-piece and stem members and an armature member extending from said stem member to said pole-piece member, a low reluctance operating flux path comprising a thin, magnetic hinge for flexibly mounting said armature member to said stem member a magnetic shunt member integral with and extending from said stem member parallel with said armature member and toward said pole-piece member, and a flux concentrator extension of said pole-piece member extending outwardly from a surface of said pole-piece member toward an opposing face of said armature member. 
     
     
       8. A miniature magnetically responsive mercury-wetted relay comprising an elongated envelope, an electrically conductive rigid magnetic stem member extending into said envelope at one end thereof, an electrically conductive rigid magnetic pole-piece member extending into said envelope at the other end thereof and opposite said stem member, a magnetic armature extending in said envelope from said stem member to adjacent said pole-piece member and overlapping said pole-piece member, and a magnetic spring hinge flexibly mounting said armature on said stem member, said pole-piece member having a flat surface facing said armature, a contact mounted on said surface for making electrical contact with said armature and a raised flux concentrating portion at the inner end thereof removed from said envelope, said raised flux concentrating portion having a flat surface substantially coplanar with the surface of said contact. 
     
     
       9. A miniature magnetically responsive mercury-wetted relay in accordance with claim 8 further comprising mercury within said envelope and a plating on said pole-piece member for preventing mercury wetting of said pole-piece member except for said surface of said contact opposite said armature.